Incandescent electric lamp



(No Model.)

W. E. NIOKERSON. INGANDESOENT ELECTRIC LAMP.

No. 500,075. Patented June 20,1893.

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UNITED STATES PATENT OFFICE.

WVILLIAM EMERY NICKERSON, OF CAMBRIDGE, MASSACHUSETTS.

INCANDESCENT ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 500,075, dated June 20,1893.

application filed Aprill, 1893. Serial No. 468,696. (No model.)

To all whom it may concern.-

Be it known that I, ILLIAM EMERY NICK- ERSON, of Cambridge, in thecounty of Middlesex and State of Massachusetts, have invented a new anduseful Improvement in Incandescent Electric Lamps, of which thefollowing, taken in connection with the accompanying drawings, is aspecification.

My invention relates to that class of incandescent electric lamps inwhich the leading-in wires are not sealed into the glass, but in whichthey are held and the neck of the lamp globe is rendered air tight, bymeans of a fusible cement.

It consists of a method of rendering such a cement more efficacious andmore easy of manipulation, as well as to reduce the quantity of certaincomponent parts required.

In the accompanying drawings, E represents the glass globe of anincandescent electric lamp having a conical neck 6.

F is the filament, attached to the leading-in wires G G at ff. The wiresG G pass through a disk 11 of mica or other suitable substance, which isof such a diameter as to loosely fit the neck of the lamp globe when inposition. The neck of the lamp globe above the disk ll is filled with acement I which serves to render the lamp globe air tight and supportfirmly the leading-in wires. This cement is poured into the neck ofthelamp globe in the melted state and may be composed substantially asfollows: pine rosin ofgood quality which is preferred to have beentreated with lime, in order to raise the melting point, three parts byweight; linseed or other equivalent oil, one part; beach sand,granulated glass or quartz, or other suitable inert substance, free frompores or volatile constituents, in granular form, five parts. In thiscement the rosin and oil form a matrix by which the particles of sand orother granular substance are surrounded and held together.

The sand, or its equivalent, accomplishes several important results.First, it requires less of the organic portion or matrix of the cementto fill the lamp neck, thereby economizing in material used. Second, asthe particles of sand,touch or nearly touch, adjacent particles, thereis little or no tendency for the mass to shrink onsolidifying. Third, ithas a tendency, somewhat analogous to that of sand in mortar, torendering the cement much firmer and less liable to fracture. Fourth,ittends to prevent the cement from running into the lamp when poured intothe neck of the globe, in case that the disk D does not exactly fit theneck of the globe. Fifth, the particles of sand being impervious to airin themselves, and the interstices being filled with the organic portionor matrix of the cement, the air in order to pass through is compelledto take a longer path through the cement than it otherwise would, and atthe same time, a less actual section of the organic portion, ispresented to the action of the air.

Instead of rosin and linseed oil, other fusible substances such ascopal, or some of the hydro-carbons of high melting point may be used.The list may be extended to some of the more readily fusible inorganicbodies, like chloride of zinc or nitrate of potassium. In fact, myinvention consists in adding to a fusible cement or matrix to be used inthe manufacture of incandescent electric lamps, a quantity of sand orits equivalent for the purpose above specified.

I claim- In an incandescent electric lamp, a fusible cement, supportingthe leading-in wires, and rendering the lamp air tight, composed of agranularsubstance, as sand and a fusible matrix, substantially as andfor the purpose set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses,on this 30th day of March, A. D.1893.

WILLIAM EMERY NICKERSON.

Witnesses:

FRANK G. PARKER, FRANK G. HATTIE.

